1. Field of the Invention
The present invention relates to an apparatus for reproducing a still image from a tape-shaped recording medium on which a still image for one picture is recorded in a multiplicity of helical tracks.
2. Description of the Related Art
In general, recording and reproduction of still image information has no limitation of time which may be experienced in recording and reproducing of a moving image. Accordingly, if a memory for at least one picture is incorporated into a digital recording and reproducing apparatus which operates at a low bit rate, it is possible to record and reproduce still image information by using such a low-bit-rate apparatus. As an example of the digital recording and reproducing apparatus, an apparatus is proposed which records and reproduces an audio-rate digital signal on a tape-shaped recording medium by means of a rotary head. The proposed apparatus is arranged to record a still image for one picture over an interval of several seconds, i.e., in several hundred tracks. For example, U.S. patent application Ser. No. 937,872 filed on Dec. 4, 1986 abandoned discloses this kind of apparatus.
In such an apparatus, a search function is important since an excessively large number of still images are recorded on a single tape. Various types of search techniques is possible, and one example is a technique in which a number is assigned to each still image or a still image recording area on a tape-shaped recording medium and the numbers are recorded on the recording medium as address information. A desired still image is searched by reproducing the address information while transporting the tape-shaped recording medium at a high speed.
In another technique, a signal is reproduced by a rotary head while a tape-shaped recording medium is being transported at a high speed, and only pixels which are reproduced from among all pixels are used to form one picture, whereby still images are displayed one after another. The technique of obtaining a reproduced image by using only reproduced pixels from among all pixels is known in the field of digital VTRs for recording and reproducing moving images. Such a technique makes it possible to obtain a reproduced image of sufficient quality which can be utilized as a search image for the moving images.
However, in a case where the technique utilizing the aforesaid address information is applied to the above-described still image reproducing apparatus, even if normal reproduction is started when address information corresponding to the number of a desired still image is reproduced, still image information corresponding to the address information cannot be completely reproduced. This is because tracing has already passed through the tracks positioned in an area in which the still image is recorded.
In the technique of obtaining a reproduced image by using only reproduced pixels from among all pixels, if a still image is searched while viewing a picture reproduced during high-speed search reproduction, a track in which the desired still image is recorded will have been passed when the still image has been reproduced. In addition, since it appears to an operator that there is no correlation between still images recorded on the tape-shaped recording medium, if the operator desires to reproduce a particular still image during the high-speed search reproduction, he must memorize still images before and after the desired still image. Such an operation will be a great burden to the operator.